The Athenaeum Portrait, also known as The Athenaeum, is an unfinished painting by Gilbert Stuart of United States President George Washington. Created in 1796, it is Stuart's most notable work. The painting depicts Washington at age 64, about three years before his death, on a brown background. It served as the model for the engraving that would be used for Washington's portrait on the United States one-dollar bill.

Gilbert Stuart was an American painter born in the Rhode Island Colony who is widely considered one of America's foremost portraitists. His best-known work is an unfinished portrait of George Washington, begun in 1796, which is usually referred to as the Athenaeum Portrait. Stuart retained the original and used it to paint scores of copies that were commissioned by patrons in America and abroad. The image of George Washington featured in the painting has appeared on the United States one-dollar bill for more than a century and on various postage stamps of the 19th century and early 20th century.